It is sometimes necessary to provide a brake for a shaft.
In some cases, it is desirable to operate the brake electrically. To this end, electrically-operated brakes have been provided. These have generally included a housing or body, a coil mounted thereon, and an armature that is selectively movable when the coil is energized. A resilient member, such as a spring, biases the armature to move away from the coil. An alternating series of friction pads and brake disks are operatively arranged between the armature and the housing, and are arranged to be compressed when the coil is de-energized. One of the pads and disks are connected to the rotating shaft, and the other of the pads and disks are connected to the housing. Hence, when the coil is de-energized, the spring urges the armature to compress the friction brake, and to brake the shaft. In some cases, it is necessary to manually rotate the shaft, or to drive the shaft without power.
In some instances, it would be highly desirable to provide an auxiliary brake that would positively lock the shaft to the housing. Such an auxiliary brake should be effective even if the shaft and housing experience substantial vibration. There is also a need for the shaft to lock automatically to prevent failure or machine damage when the shaft is no longer rotated without power. Accordingly, there is believed to have been a long-felt need for an electrically-operated shaft brake with a manually-operated positive lock and with a rotary release and automatic reset feature.